Apparatus for transferring stacks of sheet material including folded paper handkerchiefs and the like



June 24, 1969 J. FEHST ET AL 3,451,521 APPARATUS FOR TRANSFERRING STACKSOF SHEET MATERIAL INCLUDING FOLDED PAPER HANDKEHCHIEFS AND THE LIKEFiled Aug. 15, 1966 Sheet 4 June 24, 1969 J. HSYT ET AL 3,451,521

RIN

APPARATUS FOR TRANSFER TACKS OF SHEET MATERIAL INCLUDING FOLDED PAPERHANDKERCHIEFS AND THE LIKE Filed Aug. 15, 1966 Sheet 3 of 2 UnitedStates Patent US. Cl. 19824 11 Claims ABSTRACT OF THE DISCLOSURE Anapparatus for transferring stacks of sheet material from a stackingmeans to a receiving conveyor.

This invention relates in general to sheet material handling machinery,and more particularly to an apparatus for transferring stacks of sheetmaterial, such as folded paper handkerchiefs and the like, from astacking means to a receiving conveyor.

In general, the apparatus of the invention can be used with any stackingmeans, such as for example a folding machine of the type commonly usedfor folding paper handkerchiefs and napkins, or in fact any type whichstacks the material sheets one against the other into stacked groupsthat are delivered in succession upright on their lower edges from thestacking means advancing along a path extending in the direction ofstacking, and which arranges the sheets in each stack to define a commonsheet edge profile in which the edge of the first sheet of each stack isdisplaced further transversely with respect to the delivery path thanthe similar edge of any other sheet in the same stack. Such displacementof the first sheet in each stack enables the individual stacks deliveredconsecutively to be conveniently distinguished from one another. Astacking machine which provides any other suitable or equivalent meansfor distinguishing individual stacked groups of sheet material from oneanother when they are fed out in a continuous train emerging from thedelivery point of the machine, can of course be used.

Essentially, the apparatus of the invention can be considered as thecombination of a guide means, a transfer carrier means, and a retainingfinger means. The guide means in the instant invention extends from thestacking means, or more specifically from the delivery point of thestacking means, to the conveyor which is to receive the individualstacks of sheet material, and said guide means is disposed to receivesuch stacks delivered by the stacking means and to guide theiradvancement to the conveyor. The transfer carrier means is disposed atthe conveyor end of the guide means and executes repeated movementrelative thereto between one position in which it receives eachsuccessive stack upon arrival at the conveyor end of the guide means,and another position in which the transfer carrier means deposits thestacks thus received, one at a time, upon the conveyor. The retainingfinger means is also located at the conveyor end of the guide means andis arranged to execute repeated movements relative thereto insynchronism with the movement of the transfer carrier means. Theretaining finger means moves between a position of engagement with thefirst sheet of the leading stack approaching the conveyor end of theguide means to retain such stack on the guide means until the transfercarrier means has deposited a previously received stack upon theconveyor and returns to its stackreceiving position, upon which eventthe retaining finger Patented June 24, 1969 "ice means moves to adisengaged position to release the leading stack upon arrival of theconveyor end of the guide means for reception by the transfer carriermeans in its stack-receiving position. For continuous, cyclicaloperation, the retaining finger means is disposed for return movementinto its engagement position after releasing each stack, one at a time,to the transfer carrier means, and thereby engages the first sheet ofthe next stack to retain it upon the guide means until the transfercarrier means again returns to the stack-receiving position.

Folding machines for paper handkerchiefs and other such articles, aspaper napkins and the like, are often equipped with a device whichcounts olf the folded pieces and stacks them in packs containing thespecified number of pieces. As a rule, the stacks are then picked up byhand and the packs are placed into boxes in which they are brought tothe packaging machine. To enable the operator who performs this work tograsp the counted packs easily, it is in the prior art to set one packof counted pieces somewhat higher, and the next pack somewhat lower,alternately, so that the operator can conveniently grasp one pack afterthe other. It is also in the prior art to set the first piece in a packsomewhat higher, while from the second piece to the last they all remainin the lower position. In this case, too, the operator can easily pickthe individual packs from the stack. These arrangements, however, arenot suitable for automatically performing the transfer of the packs fromthe stack to a conveyor or gathering device. In an automatic transferoperation, the packs have to be so arranged that a sensing means canreliably catch the front side of each pack. If the packs are arrangedalternately higher and lower as in the prior art, such a sensing meanscan easily catch the front side of the higher-set pack, but not soreadily the front side of the next, lower-set pack. Also, in apparatusin which only the first piece of each pack is set higher, the beginningof the pack cannot be reliably detected, because the single, elevatedfolded paper handkerchief or paper napkin is too compliant, so that itcan be bent over even by the light contact pressure of the sensing meansand the sensing means can slip off it.

According to the invention, this problem is solved in that the firstpiece in the pack is raised the highest, and the height to which thesucceeding pieces are raised diminishes down to the last piece. Theupper side of the stack thereby takes on the shape of saw teeth, and thesensing means can always catch the front side of each pack, and there isno danger that, due to the compliance of the individual pieces, thesensing means could slip off, because the front piece is well supportedby the following pieces. It is not necessary that the height by whichthe individual pieces are elevated diminish uniformly from the first tothe last piece; particularly when the packs contain fairly large numbersof pieces, the lowest position in which the packs lie on the path of thestack could also be reached before the last piece: for example, in thecase of packs of 10 pieces, it could be reached by the 4th or 5th piece,so that the 5 to 6 pieces following could lie on the surface bearing thestack and in this manner the stack would be guided more securely.

At the point of transfer from the stack to the conveyor, a finger canexpediently be provided, which applies itself each time to the elevatedfirst piece of the pack, releases the first pack for transfer, and againapplies itself to the elevated first piece of the next pack following.This release of the first pack in the stack by the finger takes placewhile a transfer box is located in front of the stack, so that, when thefinger is withdrawn, the stack train can advance by about the thicknessof one pack, while the transfer box pivots to the conveyor as soon asth; finger has again caught the elevated first piece of the next packfollowing. After the transfer box has pivoted into the dumping position,a pusher can shove the pack onto a conveying means, which leads thecounted packs directly to the packaging machine. In this manner, notonly is human labor saved, but the handkerchiefs, napkins or the likeare untouched by human hand between the folding and packing operation.This is particuarly important in the case of material that has beensterilized.

In folding machinery of this kind, trouble can c casionally be caused ifthe thickness of the material being processed in the folding machine isnot entirely uniform from batch to batch and within each batch, so thatthe pressure which the folded packs in the stack exert on the retainingfinger varies considerably though the number of packs may be the same,thereby rendering the perfect operation of the transfer device doubtful.The invention further solves the problem of controlling the machineautomatically in such a manner that the pressure exerted on the fingerby the packs in the stack is always of the same magnitude, regardless ofthe thickness of the material being processed. This requires that, inthe case of thicker material, the number of packs between the foldingmachine and the transfer point is diminished, and in the case of thinnermaterial, this number is increased.

This problem is solved according to the invention in that the shaft ofthe finger of the transfer device is connected through an elasticcoupling with the drive, and the magnitude of the pivoting of the fingershaft against the drive shaft influences through a controlling devicethe operating speed of the transfer device or of the folding device, asthe case may be. The elastic coupling in other words constitutes atorque meter, and the measured torque, which is an index of the pressureexerted on the finger by the packs compressed by the finger, is kept ata desired value by the variation of the operating speed. Any torquemeasuring means of the prior art can be used to measure the torque. Anespecially simple and expedient device for the measurement of the torqueis obtained by providing on the finger shaft an arm which, when itdeviates from its predetermined setting, i.e., in the event ofexcessively great or excessively slight stack counterpressure,interrupts one of two light beams which by means of photosensitiveelements, e.g., photoelectric cells, act upon switching devices.

It is therefore, an object of the invention to provide an apparatus fortransferring stacks of sheet material from a stacking means to areceiving conveyor.

Another object of the invention is to provide an apparatus as aforesaidwhich features a guide means for guiding the advancement of sheetmaterial stacks, delivered in a consecutive train by the stacking means,to a point of transfer onto the receiving conveyor by a transfercarrier.

A further object of the invention is to provide an apparatus asaforesaid in which the stacks arriving in succession at the transferpoint on the guide means are transferred one at a time onto thereceiving conveyor by the transfer carrier.

A further object of the invention is to provide an apparatus asaforesaid in which all the stacks travelling on the guide means, exceptthe one being transferred onto the conveyor, are positively retainedupon the guide means until they, each in turn are transferred onto theconveyor.

A further object of the invention is to provide an apparatus asaforesaid which features a retaining means that operates in synchronismwith the transfer carrier to re lease one stack at a time thereto andretain all other stacks on the guide means.

A further object of the invention is to provide an apparatus asaforesaid wherein the operation of the transfer carrier can besynchronized with the stack delivery rate of the stacking means.

A further object of the invention is to provide an apparatus asaforesaid wherein the rate of stack delivery of the stacking means canbe regulated by sensing the force required to retain a column of stackson the guide means against the influence of advancing forces resultingfrom the delivery of additional stacks to the column by the stackingmeans.

Still another and further object of the invention is to provide anapparatus as aforesaid wherein the stack column retaining force isconverted into an electrical signal which can be utilized to regulatethe stack delivery rate of the stacking means.

Other and further objects and advantages of the invention will becomeapparent from the following detailed description and accompanyingdrawings in which:

FIG. 1 is a schematic elevation view of a stack transferring apparatusaccording to a preferred embodiment of the invention which is adapted totransfer onto a typical conveyor, stacks of folded paper handkerchiefsreceived from a handkerchief folding machine.

FIG. 2 is a schematic perspective view of the working portion of a stacktransferring apparatus according to another embodiment of the inventionwhich can be used in conjunction with the folding machine illustrated inFIG. 1, and which features means for controlling the operating speed ofsuch folding machine in accordance with the force exerted against theretaining means by the column of handkerchief stacks delivered by thefolding machine. i

In FIG. 1, a paper web 1 which is to be foldedinto paper handkerchiefs,is fed to a folding apparatus 2 of a conventional type, in which the web1 is folded lengthwise by the apparatus 2, and is laid in a fanfoldmanner and cut by a stacking apparatus 3. Guiding rolls 4 are placedahead of rollers provided in the apparatus 2, and their height isvaried, as indicated schematically by .a lever 5 which is moved by a cam6, such that the rolls 4 also raise and lower accordingly the web 1being fed to the folding apparatus 2. Cam 6 is so arranged that, duringthe folding of ten handkerchiefs, rolls 4 and with them the lengthwisefolded web 7 are slowly lowered from their highest position, and, afterthe folding of the tenth handkerchief, rapidly return to the uppermoststarting position. In this manner it is brought about that, in thestacks 8 of folded handkerchiefs leaving the folding and cuttingapparatus 3, the handkerchiefs or the like are arranged for a commonedgewise profile of sawtooth form as represented, in such a manner thatthe first handkerchief of each stack 8 projects above the preceedinghandkerchiefs and is supported by the handkerchiefs that follow it,advancing in succession along a guide means 31.

The transfer point, i.e. Where the stacks 8 are transferred to areceiving conveyor 15, is located at the right end of guide means 31. Apivoting finger 9 rests against the front side of the leading stack 8a.A lever 11 is swung by a rod 10, which is driven synchronously with thestacking apparatus 3, and the transfer carrier 13 is thereby swung upinto the position indicated by the broken line. As soon .as the transfercarrier 13 has reached this stack-receiving position, a spring 12 pushesfinger 9 up, so that the slightly compressed lead stack 8a expands dueto its elasticity and enters into the transfer carrier 13. When thelever 11 returns, first the finger 9 is moved back into its position ofrest and applies itself to the front side of the first, elevated foldedsheet piece in the pack next following which then becomes the lead stack8a, then the transfer carrier 13 pivots into the transfer position drawnin solid lines, and a pusher 14 pushes the stack in transfer carrier 13into the receiver of conveying means 15 located directly in front of thetransfer point, and the conveyor 15 carries the stacks to a packagingmachine (not shown). This basic process is repeated in synchronism withthe folding and stacking devices 2 and 3, the conveyor 15 beingexpediently likewise driven step.- wise in synchronism therewith.

In the apparatus of FIG. 2, the folded handkerchiefs are arranged toform a sawtooth profile column of stacks 8, as in the apparatus of FIG.1, and the finger 9 applies itself to the front side of the foremoststack. The transfer of the stacks 8 is again performed in succession, asin the apparatus of FIG. 1, in that a transfer carrier such as atransfer fork 13 is swung upward, then the finger 9 performs a swingingmovement in the direction of the arrow 18, thereby releasing theforemost stack 8a, so that it can enter into the transfer fork 13', andthe finger then returns to its position of rest and applies itself tothe front side of the next following stack 8. The shaft 19 on which thefinger 9 is fastened is connected by a schematically indicated elasticcoupling 20 to the drive shaft 21. On the shaft 19 there is furthermorefastened an arm 22, which is best made spatular in shape at its freeend. This spatular extremity of arm 22 moves between two photoelectriccell systems 23 and 24. In the proper position, i.e., when the retainingpressure of finger 9 against the stacks 8 has the value which it isintended to have, the lever 22 is between the photoelectric cellsysytems 23 and 24, so that neither of the two light beams isinterrupted. If a section of thicker web 1 material is to be processed,so that the pressure of the stacks 8 against finger 9 increases, finger9 is driven by the stack column advancing force against the resistingforce of the elastic coupling 20, rightwards in the direction ofmovement of the stacks 8, .and lever 22 tilts accordingly towardsphotoelectric cell system 23. If the light beam in this system isinterrupted during the measurement, a regulator 25, which is indicatedonly schematically, will increase the operating speed of the transferdevice 13 in accordance with the operating speed of the stacking machine3, so that more stacks are transferred per unit of time than aresupplied to take their place in the column on the guide means 31. Thenumber of stacks 8 in the column then decreases and the pressure againstfinger 9 diminishes. If the pressure against finger 9 becomes tooslight, finger 9 will be rotated leftward under the effect of theelastic coupling 20, and lever 22 will approach photoelectric cellsystem 24. If system 24 is interrupted by the spatula portion of lever22, regulator 26 will bring about a reduction of the operating speed ofthe transfer apparatus 13', so that the number of stacks 8 in the columnwill increase, until the pressure of the stacks 8 against finger 9 hasreached the proper value.

Instead of varying the operating speed of the transfer apparatus 13, itcan be kept constant and the operating speed of the stacking apparatus 3can be varied, since the ratio of the two operating speeds to oneanother is the only thing that has to be varied in order to achieve theaim of varying the number of stacks 8 between the stacking machine 3 andthe transfer apparatus 13. By this controlled variation in the number ofstacks 8 present in the column on guide means 31, the pressure of thestacks 8 against finger 9 cannot increase to the extent that finger 9 isno longer capable of holding back the stacks 8 or releases more than onestack 8 at a time, and the stack column pressure is always maintainedsufiiciently high to assure faultless feeding and uniform transfer.

As can be appreciated from the foregoing description of the invention,the transferring apparatus of the invention contemplates a stackingmeans, such as the handkerchief folding apparatus 3, which stacksmaterial sheets, such as folded handkerchiefs, one against the otherinto stacked groups 8 that are delivered in succession upright on theirlower edges advancing along a path extending in the direction ofstacking defined by the guide means 31. To distinguish one stack 8 fromanother adjoining stack 8, the stacking means 3 arranges the sheets ineach stack 8 so as to define a common edge profile, preferably thesawtoothed profile illustrted in FIGS. 1 and 2, wherein the edge of thefirst sheet of each stack 8 is displaced further transversely to thedelivery path than the similar edge of any other sheet in the same stack8. This allows the retaining finger 9 to clear the remaining sheets of alead pack 8a which has just passed into the transfer carrier 13, 13 whensaid retaining finger 9 is returned to its engagement position to holdback the following stack 8. It should be noted that while FIGS. 1 and 2illustrate stacks 8 in which the sheets have been displaced upwardly sothat their upper edges define a sawtooth profile, the transfer apparatusof the invention could just as well be adapted for operation with astacking means (not shown) which stacked groups of sheets displacedlaterally so that their lateral edges defined a sawtoothed profile. Insuch case, the retaining finger 9 would be merely arranged to swing in agenerally horizontal plane instead of the vertical plane shown in FIGS.1 and 2. It therefore can be said, that in the preferred embodiment ofthe invention, the retaining finger 9 pivots about an axis which isgenerally parallel to the sheet edges which define the sawtooth profile,such axis being also generally transverse rather than parallel to thedirection in which the stacks 8 advance on the guide means 31.

Although FIGS. 1 and 2 specifically illustrate transfer carriers 13, 13'which move pivotally with respect to the guide means 31, and pivot aboutaxes generally parallel to the retaining finger 9 pivot axes andperpendicular to the direction of stack 8 advancement, the invention isnot necessarily restricted to such specific type of transfer carrier 13,13'. In general, any transfer carrier means can be used which is capableof repeated movement relative to the guide means between one position toreceive each successive stack 8 upon arrival at the conveyor end of theguide means 31, and another position to deposit stacks 8 thus received,one at a time, upon the conveyor 15.

The retaining finger means used in the invention, essentially must becapable of repeated movement relative to the guide means in synchronismwith the movement of the transfer carrier means, and must travel betweena position of engagement with the first sheet of the leading stack 8aapproaching the conveyor end of the giude means 31, remain in suchposition of engagement to retain the leading stack 8a on the guide means31 until the transfer carrier means 13, 13' has deposited a previouslyreceived stack upon the conveyor 15 and returned to its stackreceivingposition. When the transfer carrier 13, 13' is in its stack-receivingposition, the retaining finger means must temporarily travel to itsdisengaged position to release the van leading stack to the transfercarrier 13, 13', and then return to its engaged position to retain thenext leading stack. Such return movement of the retaining finger 9 canof course be accomplished by any conventional mechanical means, such asfor example a spring 41 as illustrated in FIG. 1. Likewise, a spring 42can be used to accomplish or to aid returning the transfer carrier 13 toits stack-receiving position.

FIG. 1 illustrated a linkage means including the levers 10 and 11, andthe finger-like spring 12, which is driven in synchronism with the stackdelivery rate of the folding machine 3, and which is connected to drivethe transfer carrier 13 in synchronism with the output of said foldingmachine 3. Here the spring 12 and crank arm 43 connected to retainingfinger 9 define an intermittent motion transmission means, which byreason of spring 12 being mounted to the rocking lever 11, is driven insynchronism with the movement of the transfer carrier 13, and suchintermittent motion transmission means can be considered as beingcoupled to the finger 9 to rotatably drive same whenever the spring 12pushes against the crank 43. Thus, a cyclical intermittent swingingmovement will be imparted to the finger 9 to swing it into itsengagement position and into its disengaged position.

In FIG. 2, the elastic coupling element 20 exemplifies a generalizedtorque sensing means which is coupled to the finger 9 drive shaft 19 soas to sense the torque transmitted therethrough which maintains thefinger 9 in its position of engagement with the leading stack 8a againstthe influence of forces exerted on the finger 9 by the leading stack 8awhich forces tend to urge the finger 9 toward its disengaged position.The light beam interrupter lever 22, the photoelectric cell systems 23and 24, and the regulators 25 and 26 represent a generalized signalgenerating means which is responsive to the torque sensed by the element20 to generate a control signal corresponding to such torque and whichcontrol signal can be utilized for regulating the stack transfer rate ofthe transfer carrier 13 in relation to the stack delivery rate of thestacking means 3 so as to correspondingly regulate the number of stacks8 accumulated on the guide means 31 and thus regulate the forces whichare exerted on the finger 9 by the leading stack 8a.

While the particular type of photoelectric signal generating means shownin FIG. 2 provides a discrete, dualsignal control output, other types ofsignal generating means can be used in conjunction with specializedrequirements. For example, the torque-indicating lever 22 can be coupledto drive the arm of a potentiometer (not shown) excited 'by anelectrical voltage source so as to provide at such arm terminal anelectrical voltage signal which is an analog of the retaining finger 9stack force condition.

The photoelectric signal generating means of FIG. 2 provides an upperlimit stack force sensing photoelectric cell system 23, and a lowerlimit stack force sensing photoelectric cell system 24, which when theirindividual light beams are interrupted by lever 22, respectivelygenerate electrical control signals to increase the stack transfer rateof the transfer carrier 13' and thereby reduce the number of stacks 8accumulated on the guide means 31, or to decrease the stack transferrate and thereby increase the number of stacks 8- accumulated at a giventime. In general, for a fixed length guide means 31, the stack columnforces acting against the retaining finger 9 will rise with the numberof stacks 8 accumulated, and vice versa.

It should be noted that the number of stacks 8 accumulated on the guidemeans 31 depends on both the stack delivery rate of the stacking means 3and the stack transfer rate of the transfer carrier 13'. Where these tworates are simultaneously equal, the average number of accumulated stacks8 will remain constant. The number of accumulated stacks 8 can bereduced by raising the stack transfer rate above the stack deliveryrate, and conversely, the number of accumulated stacks 8 can beincreased by lowering the stack transfer rate below the stack deliveryrate. Therefore, to maintain the stack column forces Within apredetermined range either the stack delivery rate or the stack transferrate can be held constant while the other rate is adjusted through theapplication of a control signal derived from the operation of the torquesensing element 20.

From the foregoing, it can be appreciated by the artisan that theinvention is susceptible of numerous obvious modifications andvariations to suit the needs of a particular application. However, theinvention is intended to be limited only by the following claims inwhich We have endeavored to claim all inherent novelty.

What is claimed is:

1. An apparatus for transferring stacks of sheet material from astacking means to a receiving conveyor, said stacking means being a typewhich stacks the material sheets one against the other into stackedgroups that are delivered in succession upright on their lower edgesfrom the stacking means advancing along a path extending in thedirection of stacking, with the sheets in each stack being arranged todefine a common edge profile in which the edge of the first sheet ofeach stack is displaced further transversely to the delivery path thanthe similar edge of any other sheet in the same stack, which comprises aguide means extending from the stacking means to the conveyor anddisposed to receive such stacks delivered by the stacking means and toguide approaching the conveyor end of the guide means until theiradvancement to the conveyor, a transfer carrier means disposed at theconveyor end of said guide means and for repeated movement relativethereto between a position to receive each successive stack upon arrivalat the conveyor end of the guide means and a position to deposit thestacks thus received, one at a time, upon the conveyor, a retainingfinger means disposed at the conveyor end of said guide means and forrepeated movement relative thereto in synchronism with the movement ofthe transfer carrier means between a position of engagement with thefirst sheet of the leading stack approaching the conveyor end of theguide means to retain said stack on the guide means until the transfercarrier means has deposited a previously received stack upon theconveyor and returned to its stackreceiving position, and a disengagedposition to release said leading stack upon arrival at the conveyor endof the guide means for reception by the transfer carrier means when sameis in its stack-receiving position, said retaining finger means beingdisposed for return movement into its engagement position afterreleasing each stack, one at a time to the transfer carrier means, toengage the first sheet of the next stack to retain same upon the guidemeans until the transfer carrier means returns to its stack-receivingposition, a drive means disposed between said stacking means and theconveyor end of said guide means to synchronize the repeated movement ofsaid transfer carrier means relative to said stacking means inconjunction with the repeated movement of said retaining finger means,and, a pressure regulating means disposed between said stacking meansand the conveyor end of said guide means to regulate the operating speedof said transfer carrier means and said retaining finger means withrepeated movement relative thereto in synchronism with said stackingmeans for the control of variation in quantity of stacks, from varyinggauge of different sheet material.

2. The apparatus according to claim 1 wherein said retaining fingermeans includes a finger member disposed for pivotal movement relative tothe guide means about an axis generally transverse to the path of stackadvancement thereupon, said finger mmeber being pivotable toward theguide means into a position of engagement with the first sheet of theleading stack to retain same on the guide means, and pivotable away fromthe guide means into a disengaged position to release the leading stackfor reception by the transfer carrier means.

3. The apparatus according to claim 1 wherein said retaining fingermeans includes a drive shaft disposed for limited bi-directionalrotation about its longitudinal axis, and a finger member connected tosaid drive shaft and extending transversely outward with respect to therotation axis thereof to swing with the rotation of said shaft, saidshaft being disposed for rotation in synchronism with the movement ofthe transfer carrier means to swing the finger member toward the guidemeans and into a position of engagement with the first sheet of theleading stack to retain same on the guide means when the transfercarrier means is moved out of its stack-receiving position, and to swingthe finger member away from the guide means and into a disengagedposition to release the leading stack for reception by the transfercarrier means when same is in its stack-receiving position.

4. The apparatus according to claim 3 including a linkage means dirvenin synchronism with the stack delivery rate of said stacking means, saidlinkage means being operatively connected to said transfer carrier meansto drive same in synchronism with said stacking means, and intermittentmotion transmission means driven in synchronism with the movement ofsaid transfer carrier means and coupled to said finger member driveshaft to rotatably drive same to impart a cyclical intermittent swingingmovement to said finger member wherein said finger member is swung intoits engagement position and remains there in engagement with the firstsheet of the leading stack thereby retaining same on the guide meansuntil the transfer carrier means assumes its stackreceiving position,and upon such occurrence, said finger member is swung temporarily intoits disengaged position to release said leading stack for reception bythe transfer carrier means and then returned to its engagement positionawaiting the return of the transfer carrier means to its stack-receivingposition.

5. The apparatus according to claim 3 including torque sensing meanscoupled to said finger member drive shaft to sense the torquetransmitted therethrough to maintain said finger member in its positionof engagement with the leading stack against the influence of forcesexerted on the finger member -by said leading stack tending to urge thefinger member toward its disengaged position, and signal generatingmeans responsive to the torque sensed by said torque sensing means togenerate a control signal corresponding to said torque for regulatingthe stack transfer rate of the transfer carrier means in relation to thestack delivery rate of the stacking means to correspondingly regulatethe number of stacks accumulated on the guide means and thereby regulatethe forces exerted on the finger member by the leading stack.

6. The apparatus according to claim 5 wherein said torque sensing meansincludes an elastic torsion member coupled to said finger member driveshaft to sense the torque transmitted therethrough, and responsive tosaid torque to execute an angular displacement proportional to themagnitude thereof, and a lever connected to said torsion member toexecute an amplified angular movement in accordance with the angulardisplacement of said torsion member, and wherein said signal generatingmeans is responsive to the angular movement of said lever to generate acontrol signal corresponding to the torque, and hence the magnitude ofthe leading stack forces represented by each angular movement.

7. The apparatus according to claim 6 wherein said signal generatingmeans includes a pair of photoelectric cells and a light source meansdisposed to direct a beam of light incident upon each photoelectriccell, said photoelectric cells being each arranged at characteristicspaced apart locations along and in front of the movement path of saidlever with respect to the light source means for interruption of theirrespective incident light beams by the lever when said lever moves intoa position of registry with one of said photoelectric cells, one of saidphotoelectric cells being disposed at a location along the levermovement path corresponding to a lower limit leading stack force, andthe other photoelectric cell being disposed at a location along saidpath corresponding to an upper limit leading stack force to generaterespective electrical signals upon light beam interruptioncharacteristic of such leading stack force conditions.

8. The apparatus according to claim 7 wherein said signal generatingmeans includes a regulator means coupled to the output of eachphotoelectric cell and responsive to the electrical signal thereof togenerate a control signal to increase the stack transfer rate of saidtransfer carrier means in response to the electrical signal of the upperlimit leading stack force sensing photoelectric cell to thereby reducethe number of stacks accumulated on said guide means and thus reduce themagnitude of the leading stack forces below said upper limit value, andto generate a control signal to decrease the stack transfer rate of saidtransfer carrier means in response to the electrical signal of the lowerlimit leading stack force sensing photoelectric cell to thereby increasethe number of stacks accumulated on the guide means and thus increasesthe magnitude of the leading stack forces above said lower limit value.

9. The apparatus according to claim 1 including an ejector meansoperable in synchronism with said transfer carrier means to eject thestack received thereby onto the conveyor when said transfer carriermeans is in its stackdepositing position.

10. The apparatus according to claim 1 wherein said transfer carriermeans is disposed for pivotal movement relative to said guide meansabout an axis oriented transversely with respect to the stackadvancement path defined thereby.

11. An apparatus for transferring stacks of sheet material to areceiving conveyor which comprises a means of supplying material fromcontinuous rolls containing sheet material, a folding means, a stackinglevel guide means to adjust the height at which the means of supplyingmaterial from said supply means is variably fed to said folding means, afolding and cutting means, a stacking means to stack the material sheetsfed at a varying level of height by said stacking level guide means tosaid folding and cutting means, said stacking means being of a typewhich stacks the material sheets one against another into stacked groupsthat are delivered in successio-n upright on their lower edges from thestacking means advancing along a path extending in the direction ofstacking, with the sheets in each stack being arranged by said stackinglevel guide means to define a common edge profiling which the edge ofthe first sheet of each stack is displaced further transversely to thedelivery path than the similar edge of any other sheet in the samestack, a guide means extending from the stacking means to the conveyorand disposed to receive such stacks delivered by the stacking means andto guide their advancement to the conveyor, a transfer carrier meansdisposed at the conveyor end of said guide means and for repeatedmovement relative thereto between a position to receive each successivestack upon arrival at the conveyor end of the guide means and a positionto deposit the stacks thus received, one at a time, upon the conveyor, aretaining finger means disposed at the conveyor end of said guide meansand for repeated movement relative thereto in synchronism with themovement of the transfer carrier means between a position of engagementwith the first sheet of the leading stack approaching the conveyor endof the guide means to retain said stack on the guide means untiltransfer carrier means has deposited a previously received stack uponthe conveyor and returned to its stack receiving, and a disengagedposition to release said leading stack upon arrival at the conveyor endof the guide means for reception by the transfer carrier means when thesame is in its stack receiving position, said retaining finger meansdisposed for return movement into its engagement position afterreleasing each stack, one at a time to the transfer carrier means, toengage the first sheet of the next stack to retain same upon the guidemeans until the transfer carrier means returns to its stack receivingposition, a drive means disposed between said stacking means and theconveyor end of said guide means to synchronize the repeated movement ofsaid transfer carrier means relative to said stacking means inconjunction with the repeated movement of said retaining finger means,and, a pressure regulating means disposed between said stacking meansand the conveyor end of said guide means to regulate the operating speedof said transfer carrier means and said retaining finger means withrepeated movement relative thereto in synchronism with said stackingmeans for the control of variation in quantity of stacks from varyinggauge of different sheet material.

RICHARD E. AEGERTER, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,451,521 June 24, 1969 Jurgen Fehst et a1.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, lines 6 and 7,

"HobemaMaschinenfabrik" should read Hobema-Maschinenfabrik Hermann H.Raths Column 7, line 73, cancel "approaching the conveyor end of theguide means until".

Signed and sealed this 21st day of April 19 0.

(SEAL) Attest:

Edward M. F letcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR.

